A retrovirus that infects cats; similar to human immunodeficiency virus (HIV, the virus that causes AIDS), it attacks the immune system and as a result, the cat is more susceptible to infections that do not typically affect healthy cats.

Highly contagious disease affecting cats caused by a coronavirus (so called because of the crown or halo appearance under a microscope). Peritonitis is inflammation of the peritoneum. The virus is shed through saliva and feces.

A viral infection in cats caused by feline parvovirus (a close relative to canine parvovirus) and spread through contact with an infected cat's bodily fluids, feces, or fleas. It can result in fever, lethargy and loss of white blood cells. Also called feline distemper (but not related to canine distemper).

Spontaneous firing of a single muscle fiber not visable to the naked eye, indicative of denervation or irritable (i.e. inflammatory) myopathy; seen electrographically as a brief action potential with initial positive (down) wave followed by negative (up) wave.

The sudden blocking of blood flow to the spinal cord due to the lodging of fibrocartilage (believed to have originated from an intervertebral disk) in a blood vessel; occasionally results in ischemia and infarction of the spinal cord.